Growth and characterization of Ta/Ti bi-layer films on glass and Si (1Â 1Â 1) substrates by direct current magnetron sputtering

► The titanium adhesion layer surface characteristic plays a remarkable influence on the structural and electrical properties of the sputter deposited Ta films. ► The adhesion layer of titanium without breaking vacuum always promote the tantalum films to grow with the orientation following that of the bottom titanium layer and nucleate bcc α phase of tantalum. ► The underlying titanium film with exposure its surface to atmosphere for 24 h would restrain the nucleation of α-Ta and promote the growth of β-Ta. ► The mechanism explains the difference of the growth mode of the tantalum films.